The Denver Post: Companies, groups and other big spenders who work to support or defeat candidates and ballot measures in Denver’s local elections increasingly are operating in the shadows, city officials and good-government advocates say.

Less than two years before the next municipal election, a Denver City Council proposal seeks to close transparency gaps that allow such spending to go unreported as long as the people behind it don’t coordinate directly with a candidate’s campaign.

Such activity by super PAC-style groups has mushroomed in federal and state elections since the U.S. Supreme Court’s Citizens United decision in 2010 took the handcuffs off independent spending by corporations and labor unions, making restrictions on them unconstitutional.

Denver’s last elections for mayor, council and other city offices, in 2015, when the candidates’ own committees raised $4.6 million, brought the first hint that such activity is trickling down to the local level. Councilwoman Robin Kniech says the city is not alone across Colorado, as most local governments are behind the state in tightening campaign-finance reporting laws to require more disclosures of independent spending.